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  1. ์ถฉ๋‚จ๋Œ€ํ•™๊ต ์‚ฌํšŒ๊ธฐ๋ฐ˜์‹œ์„ค๊ธฐ์ˆ ์—ฐ๊ตฌ์†Œ ๋ฆฌ์ฒ˜์น˜ํŽ ๋กœ์šฐ (Research Fellow, Institute of Social Infrastructure Technology, Chungnam National University, Daejeon 34134, Rep. of Korea)
  2. ์ถฉ๋‚จ๋Œ€ํ•™๊ต ๊ฑด์ถ•๊ณตํ•™๊ณผ ๊ต์ˆ˜ (Professor, Department of Architectural Engineering, Chungnam National University, Daejeon 34134, Rep. of Korea)
  3. ํ•œ๊ตญ๊ฑด์„ค๊ธฐ์ˆ ์—ฐ๊ตฌ์› ๊ตญ๋ฏผ์ƒํ™œ์—ฐ๊ตฌ๋ณธ๋ถ€ ๊ฑด์ถ•์•ˆ์ „์„ผํ„ฐ ์ˆ˜์„์—ฐ๊ตฌ์› (Senior Researcher, Building Safety Research Center, Department of Living and Built Environment Research, Korea Institute of Civil Engineering and Building Technology, Goyang 10223, Rep. of Korea)
  4. ์ถฉ๋‚จ๋Œ€ํ•™๊ต ๊ฑด์ถ•๊ณตํ•™๊ณผ ๋Œ€ํ•™์›์ƒ (Graduate Student, Department of Architectural Engineering, Chungnam National University, Daejeon 34134, Rep. of Korea)



๊ณ ๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ, ๋น„์ •์งˆ ๊ฐ•์„ฌ์œ , ์••์ถ•๊ฐ•๋„, ํƒ„์„ฑ๊ณ„์ˆ˜, ์—ดํŒฝ์ฐฝ๋ณ€ํ˜•
high strength concrete, amorphous steel fiber, compressive strength, elastic modulus, thermal expansion strain

1. ์„œ ๋ก 

์ฝ˜ํฌ๋ฆฌํŠธ๋Š” ํ™”์žฌ์™€ ๊ฐ™์€ ๊ณ ์˜จ์— ๊ฐ•ํ•œ ์žฌ๋ฃŒ๋กœ ์ธ์‹๋˜์–ด์™”์œผ๋‚˜ ๊ณ ์˜จ ๊ฐ€์—ด์„ ๋ฐ›์€ ์ฝ˜ํฌ๋ฆฌํŠธ๋Š” ๊ตฌ์„ฑ ์žฌ๋ฃŒ์˜ ์—ดํŒฝ์ฐฝ ๊ฑฐ๋™๊ณผ ์ˆ˜ํ™”๋ฌผ์˜ ํƒˆ์ˆ˜ ๋“ฑ์œผ๋กœ ์ธํ•œ ๋ฌผ๋ฆฌ๏ฝฅํ™”ํ•™์  ๋ณ€ํ™”๊ฐ€ ๋ฐœ์ƒํ•œ๋‹ค(Khoury 2000; Franssen and Dotreppe 2003; Schneider and Schneider 2009). ์ด๋Ÿฌํ•œ ๋ณ€ํ™”๋Š” ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์—ญํ•™์  ์„ฑ๋Šฅ ์ €ํ•˜์— ์ง์ ‘์ ์ธ ์˜ํ–ฅ์„ ๋ฏธ์น˜๊ธฐ ๋•Œ๋ฌธ์— ์ฝ˜ํฌ๋ฆฌํŠธ๋ฅผ ์‚ฌ์šฉํ•œ ๊ฑด์ถ•๊ตฌ์กฐ๋ฌผ์˜ ํ™”์žฌ์•ˆ์ „์„ฑ๋Šฅ์„ ์˜ˆ์ธกํ•˜๊ธฐ ์œ„ํ•ด์„œ๋Š” ๊ณ ์˜จ์„ ๋ฐ›์€ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์—ญํ•™์  ํŠน์„ฑ์— ๋Œ€ํ•œ ์ดํ•ด๊ฐ€ ํ•„์š”ํ•˜๋‹ค.

๊ณ ์˜จ ํ™˜๊ฒฝ์— ๋…ธ์ถœ๋œ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์—ญํ•™์  ํŠน์„ฑ์€ 1950๋…„๋Œ€๋ฅผ ์‹œ์ž‘์œผ๋กœ ์—ฌ๋Ÿฌ ์—ฐ๊ตฌ์ž์— ์˜ํ•ด ๊ฒ€ํ† ๋˜์—ˆ๋‹ค. ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์••์ถ•๊ฐ•๋„, ๊ตต์€ ๊ณจ์žฌ์˜ ์ข…๋ฅ˜, ๊ฐ€์—ด์˜จ๋„ ๋ฐ ํ•˜์ค‘์กฐ๊ฑด ๋“ฑ ๋‹ค์–‘ํ•œ ์‹คํ—˜๋ณ€์ˆ˜๋ฅผ ์ ์šฉํ•œ ์—ฐ๊ตฌ๊ฐ€ ์ง„ํ–‰๋˜์—ˆ์œผ๋ฉฐ, ๊ฐ€์—ด์˜จ๋„์— ๋”ฐ๋ฅธ ์••์ถ•๊ฐ•๋„, ํƒ„์„ฑ๊ณ„์ˆ˜ ๋ฐ ์—ดํŒฝ์ฐฝ๋ณ€ํ˜•์ด ์ฃผ๋กœ ํ‰๊ฐ€๋˜์—ˆ๋‹ค(Malhotra 1956; Abrams 1971; Schneider 1988).

๊ณ ๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ๊ณ ์˜จ ํŠน์„ฑ์— ๊ด€ํ•œ ์—ฐ๊ตฌ๋Š” ์ฃผ๋กœ ํญ๋ ฌ์— ์ค‘์ ์„ ๋‘” ์—ฐ๊ตฌ๊ฐ€ ๋งŽ์ด ์ง„ํ–‰๋˜์—ˆ์œผ๋ฉฐ, ํด๋ฆฌํ”„๋กœํ•„๋ Œ ์„ฌ์œ ์™€ ๊ฐ™์€ ์œ ๊ธฐ์„ฌ์œ ๋‚˜ ๊ฐ•์„ฌ์œ ์˜ ํ˜ผ์ž…์— ์˜ํ•ด ํญ๋ ฌ์„ ์ œ์–ดํ•  ์ˆ˜ ์žˆ๋Š” ๊ฒƒ์œผ๋กœ ๋ณด๊ณ ๋˜๊ณ  ์žˆ๋‹ค(Liu et al. 2008; Ding et al. 2016). ํ•œํŽธ, ๊ณ ๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ๋Š” ์ƒ๋Œ€์ ์œผ๋กœ ๊ฒฐํ•ฉ์žฌ์˜ ์–‘์ด ๋งŽ๊ณ  ์กฐ์ง๊ตฌ์กฐ๊ฐ€ ์น˜๋ฐ€ํ•˜๊ธฐ ๋•Œ๋ฌธ์— ๊ณ ์˜จ ํ™˜๊ฒฝ์—์„œ ์ผ๋ฐ˜๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ๋ณด๋‹ค ๊ฐ•๋„ ์ €ํ•˜ ๋น„์œจ์ด ๋†’์€ ๊ฒƒ์œผ๋กœ ๋ณด๊ณ ๋˜๊ณ  ์žˆ์œผ๋ฉฐ, ์ด๋Š” ํญ๋ ฌ๊ณผ ๋”๋ถˆ์–ด ๊ณ ๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ๋ฌธ์ œ์ ์œผ๋กœ ์ง€์ ๋˜๊ณ  ์žˆ๋‹ค(Phan and Carino 2001; Choe et al. 2013).

๊ณ ๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ์— ๋‹ค์–‘ํ•œ ์„ฌ์œ ๋ฅผ ํ˜ผ์ž…ํ•˜๋Š” ๋ฐฉ๋ฒ•์€ ํญ๋ ฌ์ œ์–ด ๋ฟ๋งŒ ์•„๋‹ˆ๋ผ ๊ณ ์˜จ์— ๋…ธ์ถœ๋œ ๊ณ ๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์—ญํ•™ ์„ฑ๋Šฅ์„ ๊ฐœ์„ ํ•˜๋Š” ๊ฒƒ์—๋„ ํšจ๊ณผ๊ฐ€ ์žˆ๋Š” ๊ฒƒ์œผ๋กœ ๋ณด๊ณ ๋˜๊ณ  ์žˆ๋‹ค. Behnood and Ghandehari(2009)๋Š” ํด๋ฆฌํ”„๋กœํ•„๋ Œ ์„ฌ์œ ์˜ ํ˜ผ์ž…์— ์˜ํ•ด ๊ณ ์˜จ ๊ฐ€์—ด๋œ ๊ณ ๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์ž”์กด ์—ญํ•™์  ํŠน์„ฑ์„ ๊ฐœ์„ ํ•  ์ˆ˜ ์žˆ๋Š” ๊ฒƒ์„ ํ™•์ธํ•˜์˜€๋‹ค. ๋˜ํ•œ, Chen and Liu(2004)๋Š” ๊ฐ•์„ฌ์œ ์™€ ๊ฐ™์€ ๊ณ ํƒ„์„ฑ์˜ ์„ฌ์œ ๋Š” ์ฝ˜ํฌ๋ฆฌํŠธ ๋‚ด๋ถ€์—์„œ ๊ฐ€๊ต๊ฒฐํ•ฉ ํ•จ์œผ๋กœ์จ ์˜จ๋„์ƒ์Šน์— ์˜ํ•œ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์ฒด์ ๋ณ€ํ™” ๋ฐ ๋ฏธ์„ธ๊ท ์—ด์˜ ๋ฐœ์ƒ๊ณผ ํ™•์žฅ์„ ์–ต์ œํ•  ์ˆ˜ ์žˆ์œผ๋ฏ€๋กœ ๊ณ ์˜จ์— ๋…ธ์ถœ๋œ ๊ณ ๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์—ญํ•™์  ์„ฑ๋Šฅ์ €ํ•˜๋ฅผ ์™„ํ™”ํ•  ์ˆ˜ ์žˆ๋‹ค๊ณ  ๋ณด๊ณ ํ•˜์˜€๋‹ค.

์ตœ๊ทผ์—๋Š” ๋น„์ •์งˆ ๊ฐ•์„ฌ์œ ๋กœ ๋ณด๊ฐ•๋œ ์ฝ˜ํฌ๋ฆฌํŠธ๊ฐ€ ์†Œ๊ฐœ๋˜๊ณ  ์žˆ๋‹ค. ๋น„์ •์งˆ ๊ฐ•์„ฌ์œ ๋Š” ์ƒ์‚ฐ๊ณผ์ •์ด ๋น„๊ต์  ๊ฐ„๋‹จํ•ด์„œ ๊ฒฝ์ œ์ ์ด๊ณ  ์นœํ™˜๊ฒฝ์ ์ธ ๊ฒƒ์œผ๋กœ ์ธ์ •๋˜๊ณ  ์žˆ์œผ๋ฉฐ(Yang et al. 2017), ์ธ์žฅ๊ฐ•๋„๊ฐ€ ๋†’๊ณ  ๋น„์ค‘์ด ์ž‘์œผ๋ฉฐ ๋ถ€์‹์— ๋Œ€ํ•œ ์ €ํ•ญ์„ฑ์ด ๋†’์€ ํŠน์ง•์ด ์žˆ๋‹ค. ๋”ฐ๋ผ์„œ, ๋‹ค์–‘ํ•œ ์—ฐ๊ตฌ๋ฅผ ํ†ตํ•ด ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ๋ณด๊ฐ•์žฌ๋กœ ์ ์šฉ๋˜์–ด ์ธ์žฅ ํŠน์„ฑ, ์••์ถ•๊ฐ•๋„, ๊ท ์—ด ์ œ์–ด ์„ฑ๋Šฅ์ด ๊ฒ€ํ† ๋˜์—ˆ๋‹ค(Won et al. 2013; Choi et al. 2014; Yoo et al. 2016; Seo et al. 2017).

ํ•œํŽธ, ์•ž์„œ ์–ธ๊ธ‰ํ•œ ๋ฐ”์™€ ๊ฐ™์ด ๊ณ ์˜จ ํ™˜๊ฒฝ์— ๋…ธ์ถœ๋œ ๊ณ ๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์—ญํ•™์  ์„ฑ๋Šฅ์— ๊ด€ํ•ด์„œ๋Š” ์žฌ๋ฃŒ ๋ฐ ํ™˜๊ฒฝ์  ์กฐ๊ฑด์— ๋”ฐ๋ผ ๋‹ค์–‘ํ•œ ์—ฐ๊ตฌ๊ฐ€ ์ˆ˜ํ–‰๋˜์—ˆ์œผ๋‚˜ ๊ณ ์˜จ์— ๋…ธ์ถœ๋œ ๋น„์ •์งˆ ๊ฐ•์„ฌ์œ  ํ˜ผ์ž… ๊ณ ๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์—ญํ•™์  ํŠน์„ฑ์„ ํ‰๊ฐ€ํ•œ ์—ฐ๊ตฌ์‚ฌ๋ก€๋Š” ์ถฉ๋ถ„ํ•˜์ง€ ์•Š์€ ์‹ค์ •์ด๋‹ค.

๋”ฐ๋ผ์„œ, ์ด ์—ฐ๊ตฌ์—์„œ๋Š” ๊ฐ€์—ด์˜จ๋„์— ๋”ฐ๋ฅธ ๋น„์ •์งˆ ๊ฐ•์„ฌ์œ ๋ณด๊ฐ• ๊ณ ๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์‘๋ ฅ-๋ณ€ํ˜• ๊ด€๊ณ„, ์••์ถ•๊ฐ•๋„, ํƒ„์„ฑ๊ณ„์ˆ˜, ์ตœ๋Œ€๋ณ€ํ˜• ๋ฐ ์—ดํŒฝ์ฐฝ๋ณ€ํ˜• ๋“ฑ์˜ ์—ญํ•™์  ํŠน์„ฑ์„ ํ‰๊ฐ€ํ•จ์œผ๋กœ์จ ๋น„์ •์งˆ ๊ฐ•์„ฌ์œ ์˜ ํ˜ผ์ž…์ด ๊ณ ์˜จ ํ™˜๊ฒฝ์— ๋…ธ์ถœ๋œ ๊ณ ๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์—ญํ•™์  ์„ฑ๋Šฅ์— ๋ฏธ์น˜๋Š” ์˜ํ–ฅ์„ ์‹คํ—˜์ ์œผ๋กœ ๊ฒ€ํ† ํ•˜์˜€๋‹ค.

2. ์‹คํ—˜๊ณ„ํš ๋ฐ ๋ฐฉ๋ฒ•

2.1 ์‚ฌ์šฉ์žฌ๋ฃŒ

Table 1์€ ์„ฌ์œ ๋ณด๊ฐ• ๊ณ ๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ ์‹œํ—˜์ฒด ์ œ์ž‘์— ์‚ฌ์šฉ๋œ ์žฌ๋ฃŒ์˜ ์ข…๋ฅ˜์™€ ๋ฌผ๋ฆฌ์  ์„ฑ์งˆ์„ ๋‚˜ํƒ€๋‚ธ๋‹ค. ์‹œ๋ฉ˜ํŠธ๋Š” 1์ข… ๋ณดํ†ตํฌํ‹€๋žœ๋“œ์‹œ๋ฉ˜ํŠธ๋ฅผ ์‚ฌ์šฉํ•˜์˜€์œผ๋ฉฐ, ํ˜ผํ™”์žฌ๋Š” ๊ณ ๋กœ์Šฌ๋ž˜๊ทธ ๋ฏธ๋ถ„๋ง, ์„๊ณ  ๋ฐ ์‹ค๋ฆฌ์นดํ“ธ์„ ์‚ฌ์šฉํ•˜์˜€๋‹ค. ์ž”๊ณจ์žฌ๋Š” ์กฐ๋ฆฝ๋ฅ  2.6๋กœ ์ฝ˜ํฌ๋ฆฌํŠธํ‘œ์ค€์‹œ๋ฐฉ์„œ(KCI 2009)์—์„œ ์ •ํ•˜๊ณ  ์žˆ๋Š” ์ž…๋„๋ถ„ํฌ ๊ณก์„ ์˜ ๋ฒ”์œ„๋ฅผ ๋งŒ์กฑํ•˜๋ฉฐ ํก์ˆ˜์œจ 1 %์ธ ๊ฐ•๋ชจ๋ž˜๋ฅผ ์‚ฌ์šฉํ•˜์˜€๋‹ค. ๊ตต์€ ๊ณจ์žฌ๋Š” ์ตœ๋Œ€์น˜์ˆ˜ 20 mm์˜ ํ™”๊ฐ•์•” ์‡„์„์„ ์‚ฌ์šฉํ•˜์˜€๋‹ค. ๊ณ ๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์œ ๋™์„ฑ์„ ํ™•๋ณดํ•˜๊ธฐ ์œ„ํ•ด ํด๋ฆฌ์นด๋ฅด๋ณธ์‚ฐ๊ณ„ ๊ณ ์„ฑ๋Šฅ ๊ฐ์ˆ˜์ œ๋ฅผ ์‚ฌ์šฉํ•˜์˜€์œผ๋ฉฐ, ๋ฐฐํ•ฉ์กฐ๊ฑด์— ๋”ฐ๋ผ ์‹œ๋ฉ˜ํŠธ ์ค‘๋Ÿ‰์˜ 0.9~1.2 %๋ฅผ ์ฒจ๊ฐ€ํ•˜์˜€๋‹ค.

Table 1. Physical properties of materials

Materials

Physical properties

Cement (C)

Ordinary portland type 1 cement,

Density: 3.15 g/cm$^3$,

Fineness: 3,200 cm$^2$/g

Blast furnace slag (BFS)

Density: 2.50 g/cm$^3$,

Fineness: 6,000 cm$^2$/g

Silica fume (SF)

Density: 2.50 g/cm$^3$,

Fineness: 200,000 cm$^2$/g

Gypsum (Gy)

Density: 2.90 g/m$^3$,

Fineness: 3,550 cm$^2$/g

Coarse aggregate (G)

Crushed granitic aggregate,

Maximum size: 20 mm,

Density: 2.70 g/cm$^3$,

Absorption: 0.9 %

Fine aggregate (S)

River sand, Density: 2.65 g/cm$^3$, Absorption: 1 %, F.M.: 2.6

Super plasticizer

Polycarboxylic-based super plasticizer

Amorphous steel fiber (A)

Length: 30 mm, Width: 1.6 mm, Thickness: 29 ยตm, Density: 7.2 g/cm$^3$

Polypropylene fiber (PP)

Length: 15 mm, Diameter: 20 ยตm

Density: 0.91 g/cm$^3$,

Melting point: 170 ยฐC

์„ฌ์œ ๋Š” ๊ธธ์ด 30 mm, ํญ 1.6 mm, ๋‘๊ป˜ 29 ยตm, ๋ฐ€๋„ 7.2 g/cm$^3$ ๋ฐ ์ธ์žฅ๊ฐ•๋„ 1,400 MPa์ธ ๋น„์ •์งˆ ๊ฐ•์„ฌ์œ ์™€ ๊ธธ์ด 15 mm, ์ง๊ฒฝ 20 ยตm, ๋ฐ€๋„ 0.91 g/cm$^3$ ๋ฐ ์šฉ์œต์  170 ยฐC์ธ ํด๋ฆฌํ”„๋กœํ•„๋ Œ ์„ฌ์œ ๋ฅผ ์‚ฌ์šฉํ•˜์˜€๋‹ค.

2.2 ์‹คํ—˜๊ณ„ํš ๋ฐ ์ฝ˜ํฌ๋ฆฌํŠธ ๋ฐฐํ•ฉ

Table 2์™€ Table 3์€ ๋ณธ ์—ฐ๊ตฌ์˜ ์‹คํ—˜๊ณ„ํš๊ณผ ๊ณ ๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ๋ฐฐํ•ฉ์„ ๋ณด์—ฌ์ค€๋‹ค. ์ฝ˜ํฌ๋ฆฌํŠธ๋Š” ์••์ถ•๊ฐ•๋„๊ฐ€ 100๊ณผ 120 MPa์˜ ๊ณ ๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ๊ฐ€ ์‚ฌ์šฉ๋˜์—ˆ๋‹ค. ์„ฌ์œ ๋Š” ํด๋ฆฌํ”„๋กœํ•„๋ Œ ์„ฌ์œ ์™€ ๋น„์ •์งˆ ๊ฐ•์„ฌ์œ ๋ฅผ ํ•จ๊ป˜ ์‚ฌ์šฉํ•˜์˜€๋‹ค. ๊ฐ๊ฐ์˜ ์„ฌ์œ ๋Š” ์ฝ˜ํฌ๋ฆฌํŠธ ์ „์ฒด ๋ถ€ํ”ผ์— ๋Œ€ํ•œ ๋ฐฑ๋ถ„์œจ(vol%)๋กœ ํ˜ผ์ž…๋˜์—ˆ๋‹ค. ํด๋ฆฌํ”„๋กœํ•„๋ Œ ์„ฌ์œ ์˜ ํ˜ผ์ž…๋ฅ ์€ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์••์ถ•๊ฐ•๋„์— ๋”ฐ๋ผ 0.15($f_{c}$=100 MPa) ๋ฐ 0.25 vol%($f_{c}$=120 MPa)๋กœ ์„ค์ •ํ–ˆ๋‹ค. ๋น„์ •์งˆ ๊ฐ•์„ฌ์œ ์˜ ํ˜ผ์ž…๋ฅ ์€ 0.0, 0.3 ๋ฐ 0.5 vol%์˜ 3์ข…๋ฅ˜๋กœ ์„ค์ •ํ•˜์˜€๋‹ค.

Table 2. Experimental plan

ID

$f_{c}$

(MPa)

Fiber contents

(vol%)

Parameters

PP

A

100P15

100

0.15

0.0

Stress-strain

Compressive strength (MPa)

Elastic modulus (GPa)

Peak strain (ฮต)

Thermal expansion strain (ฮต)

100P15A30

100

0.15

0.3

100P15A50

100

0.15

0.5

120P25

120

0.25

0.0

120P25A30

120

0.25

0.3

120P25A30

120

0.25

0.5

Table 3. Mixture proportions of high strength concrete

W/B

$f_{c}$

(MPa)

Slump-flow$^{1)}$

(mm)

Air$^{2)}$

(%)

S/a

(%)

Water

(kg/m$^3$)

Unit weight (kg/m$^3$)

C

SF

BFS

Gy

S

G

0.19

100

650ยฑ50

2ยฑ1

45

160

589

126

126

0

617

740

0.15

120

693

160

160

53

513

615

$^{1)}$KS F 2594 (KATS 2015), $^{2)}$KS F 2409 (KATS 2016)

๋ชฉํ‘œ ๊ฐ€์—ด์˜จ๋„๋Š” 100, 200, 300, 500 ๋ฐ 700 ยฐC๋กœ ์ •ํ•˜๊ณ  1 ยฐC/min.๋กœ ๊ฐ€์—ดํ–ˆ๋‹ค. ๋ชฉํ‘œ ์˜จ๋„๊นŒ์ง€ ๊ฐ€์—ด๋œ ์ฝ˜ํฌ๋ฆฌํŠธ ์‹œํ—˜์ฒด๋ฅผ ํ•ญ์˜จํ•ญ์Šต์กฐ๊ฑด์—์„œ 24์‹œ๊ฐ„ ๋™์•ˆ ์ž์—ฐ ๋ƒ‰๊ฐํ•œ ํ›„์— ์‘๋ ฅ-๋ณ€ํ˜• ๊ณก์„ , ์••์ถ•๊ฐ•๋„, ํƒ„์„ฑ๊ณ„์ˆ˜ ๋ฐ ์ตœ๋Œ€๋ณ€ํ˜•์„ ํ‰๊ฐ€ํ•˜๊ณ  ์—ดํŒฝ์ฐฝ๋ณ€ํ˜•์€ 700 ยฐC๊นŒ์ง€ ๊ฐ€์—ด๋˜๋Š” ๋™์•ˆ์— ๋ฐœ์ƒํ•˜๋Š” ์‹œํ—˜์ฒด์˜ ๋ณ€ํ˜•๋Ÿ‰์œผ๋กœ ํ‰๊ฐ€ํ–ˆ๋‹ค.

2.3 ์‹œํ—˜์ฒด ์ œ์ž‘ ๋ฐ ์–‘์ƒ ๋ฐฉ๋ฒ•

์ฝ˜ํฌ๋ฆฌํŠธ ์‹œํ—˜์ฒด๋Š” KS F 2403 ๏ฝข์ฝ˜ํฌ๋ฆฌํŠธ์˜ ๊ฐ•๋„์‹œํ—˜์šฉ ์‹œํ—˜์ฒด ์ œ์ž‘๋ฐฉ๋ฒ•๏ฝฃ(KATS 2014)์— ์ค€ํ•˜์—ฌ ์ง€๋ฆ„ 100 mm, ๋†’์ด 200 mm์˜ ์›์ฃผํ˜•์œผ๋กœ ์ œ์ž‘ํ•˜์˜€๋‹ค. ์ œ์ž‘๋œ ์‹œํ—˜์ฒด๋Š” ํƒˆํ˜• ํ›„ ์žฌ๋ น 28์ผ๊นŒ์ง€ ์˜จ๋„ 20ยฑ2 ยฐC์˜ ์ˆ˜์กฐ์—์„œ ์ˆ˜์ค‘ ์–‘์ƒํ•œ ํ›„, ํ•ญ์˜จํ•ญ์Šต์กฐ๊ฑด(์˜จ๋„ 20ยฑ2 ยฐC, ์ƒ๋Œ€์Šต๋„ 60ยฑ5 %)์—์„œ ์žฌ๋ น 180์ผ๊นŒ์ง€ ์–‘์ƒํ–ˆ๋‹ค. ๊ฐ€์—ด์‹คํ—˜ ์ „, Schneider et al.(2000)์ด ์ œ์•ˆํ•˜๊ณ  ์žˆ๋Š” ๋ฐฉ๋ฒ•์— ์˜ํ•ด ์ธก์ •ํ•œ ์‹œํ—˜์ฒด์˜ ํ•จ์ˆ˜์œจ์€ ํ‰๊ท  2.7 %(ํ‘œ์ค€ํŽธ์ฐจ 0.063)์ด์—ˆ๋‹ค.

2.3 ์‹œํ—˜์ฒด ์ œ์ž‘ ๋ฐ ์–‘์ƒ ๋ฐฉ๋ฒ•

2.4.1 ๊ฐ€์—ด๋ฐฉ๋ฒ•

๋ณธ ์—ฐ๊ตฌ์—์„œ ์‚ฌ์šฉํ•œ ๊ฐ€์—ด์žฅ์น˜๋Š” Fig. 1์— ๋‚˜ํƒ€๋‚ธ ๋ฐ”์™€ ๊ฐ™์ด 2,000 kN๊ธ‰ UTM์— ์ „๊ธฐํžˆํ„ฐ๊ฐ€ ๊ฒฐํ•ฉ๋œ ํ˜•ํƒœ๋กœ ์‹œํ—˜์ฒด์˜ ๊ณ ์ •์„ ๋ชฉ์ ์œผ๋กœ ๊ฐ€์—ด ์‹œ์ž‘ 3์‹œ๊ฐ„ ์ „์— 50 kN๋ฅผ ์žฌํ•˜ํ•˜๊ณ  ๊ฐ€์—ด๊ณผ์ •์—์„œ ์ผ์ •ํ•˜๊ฒŒ ์œ ์ง€๋˜๋„๋ก ์„ค์ •ํ•˜์˜€๋‹ค. ๊ฐ€์—ด์€ Fig. 2์™€ ๊ฐ™์ด ์„ค์ •๋œ ๊ฐ€์—ด๊ณก์„ ์„ ์ด์šฉํ•ด์„œ ์‹œํ—˜์ฒด๋ฅผ ๊ณ ์ •ํ•˜๊ณ  ์žˆ๋Š” ์ƒ๋ถ€์™€ ํ•˜๋ถ€์˜ ์ง€๊ทธ๋ฅผ ๊ฐ€์—ดํ•จ์œผ๋กœ์จ ์—ด์„ ์‹œํ—˜์ฒด๋กœ ์ „๋‹ฌํ•˜๋Š” ๋ฐฉ์‹์„ ์ ์šฉํ–ˆ๋‹ค. ์—ด์„ ํšจ๊ณผ์ ์œผ๋กœ ์ „๋‹ฌํ•˜๊ธฐ ์œ„ํ•ด ์ฝ˜ํฌ๋ฆฌํŠธ ์‹œํ—˜์ฒด ํ‘œ๋ฉด์„ ๊ฐ•์žฌ ์ปค๋ฒ„๋กœ ๊ฐ์ŒŒ์œผ๋ฉฐ, ๊ตฌ์† ํšจ๊ณผ๋ฅผ ์ œ๊ฑฐํ•˜๊ธฐ ์œ„ํ•ด ๊ฐ•์žฌ ์ปค๋ฒ„๋ฅผ 8๊ฐœ๋กœ ๋ถ„ํ• ํ•˜๊ณ  ์Šคํ”„๋ง์œผ๋กœ ์ฒด๊ฒฐํ–ˆ๋‹ค.

2.4.2 ์••์ถ•๊ฐ•๋„ ๋ฐ ํƒ„์„ฑ๊ณ„์ˆ˜

์••์ถ•๊ฐ•๋„ ๋ฐ ํƒ„์„ฑ๊ณ„์ˆ˜๋Š” KS F 2405 ๏ฝข์ฝ˜ํฌ๋ฆฌํŠธ ์••์ถ•๊ฐ•๋„ ์‹œํ—˜๋ฐฉ๋ฒ•๏ฝฃ(KATS 2010) ๋ฐ KS F 2438 ๏ฝข์ฝ˜ํฌ๋ฆฌํŠธ ์›์ฃผ ๊ณต์‹œ์ฒด์˜ ์ •ํƒ„์„ฑ๊ณ„์ˆ˜ ๋ฐ ํฌ์•„์†ก๋น„ ์‹œํ—˜๋ฐฉ๋ฒ•๏ฝฃ(KATS 2017)์— ์ค€ํ•˜์—ฌ ์ธก์ •ํ•˜์˜€๋‹ค. ์••์ถ•ํ•˜์ค‘์€ ์ดˆ๋‹น 0.3 N/mm$^2$ ์†๋„๋กœ ์žฌํ•˜ํ•˜์˜€์œผ๋ฉฐ ๋ณ€ํ˜•์€ ์‹œํ—˜์ฒด ์ขŒ์šฐ์— ๋ณ€์œ„๊ณ„๋ฅผ ์„ค์น˜ํ•˜๊ณ  ๋‘ ๋ณ€์œ„๊ณ„์—์„œ ์ธก์ •๋œ ๊ฐ’์˜ ํ‰๊ท ์„ ์‚ฌ์šฉํ•˜์˜€๋‹ค. ์ตœ๋Œ€๋ณ€ํ˜•์€ EN 1992-1-2:2004(CEN 2004)์— ์˜ํ•ด ์ •์˜ํ•˜์˜€๋‹ค.

2.4.3 ์—ดํŒฝ์ฐฝ๋ณ€ํ˜•

์ฝ˜ํฌ๋ฆฌํŠธ ์‹œํ—˜์ฒด์˜ ๊ฐ€์—ด์‹œํ—˜์—์„œ๋Š” ์‹œํ—˜์ฒด๋ฅผ ๊ณ ์ •ํ•˜๊ณ  ์žˆ๋Š” ์‹œํ—˜์žฅ์น˜๊ฐ€ ๋™์‹œ์— ๊ฐ€์—ด๋˜์–ด ๋ณ€ํ˜•์„ ์ผ์œผํ‚ค๊ธฐ ๋•Œ๋ฌธ์— ์˜จ๋„์ƒ์Šน์— ์˜ํ•œ ์ฝ˜ํฌ๋ฆฌํŠธ ์‹œํ—˜์ฒด์˜ ๋…๋ฆฝ์ ์ธ ๋ณ€ํ˜•์„ ์ธก์ •ํ•˜๋Š” ๊ฒƒ์€ ๋งค์šฐ ์–ด๋ ค์šด ์ผ์ด๋‹ค. ๋ณธ ์—ฐ๊ตฌ์—์„œ๋Š” Fig. 3์— ๋‚˜ํƒ€๋‚ธ ๋ฐ”์™€ ๊ฐ™์ด ์ƒ๋ถ€์— ์„ค์น˜๋œ ๋ณ€์œ„๊ณ„์—์„œ ์ธก์ •๋œ ๋ณ€ํ˜•($\Delta L_{1}$)๊ณผ ํ•˜๋ถ€์— ์„ค์น˜๋œ ๋ณ€์œ„๊ณ„์—์„œ ์ธก์ •๋œ ๋ณ€ํ˜•($\Delta L_{2}$)์„ ์ด์šฉํ•˜์—ฌ ์‹ (1)์— ์˜ํ•ด ์ฝ˜ํฌ๋ฆฌํŠธ ์—ดํŒฝ์ฐฝ๋ณ€ํ˜•($\Delta L_{c}$)์„ ์‚ฐ์ถœํ•˜์˜€๋‹ค.

Fig. 1. Heating device

../../Resources/kci/JKCI.2020.32.1.019/fig1.png

Fig. 2. Heating temperature

../../Resources/kci/JKCI.2020.32.1.019/fig2.png

Fig. 3. Overview of measuring thermal expansion strain

../../Resources/kci/JKCI.2020.32.1.019/fig3.png

(1)
$$\Delta L_{c}=\Delta L_{2}-\Delta L_{1}$$ $$ \begin{aligned} ์—ฌ๊ธฐ์„œ, \enspace & \Delta L_{c}: \text{์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์—ดํŒฝ์ฐฝ๋Ÿ‰(mm)}\\ &\Delta L_{1}: \text{์ƒ๋ถ€๋ณ€์œ„๊ณ„์˜ ๋ณ€ํ˜•๋Ÿ‰(mm)}\\ &\Delta L_{2}: \text{ํ•˜๋ถ€๋ณ€์œ„๊ณ„์˜ ๋ณ€ํ˜•๋Ÿ‰(mm)} \end{aligned} $$

3. ์‹คํ—˜๊ฒฐ๊ณผ ๋ฐ ๊ณ ์ฐฐ

3.1 ์‘๋ ฅ-๋ณ€ํ˜•

Fig. 4์— ๋ชฉํ‘œ ์˜จ๋„๋กœ ๊ฐ€์—ด๋œ ์„ฌ์œ ๋ณด๊ฐ• ๊ณ ๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ ์‹œํ—˜์ฒด์˜ ์‘๋ ฅ-๋ณ€ํ˜• ๊ณก์„ ์„ ๋‚˜ํƒ€๋ƒˆ๋‹ค. ๋ณธ ์—ฐ๊ตฌ์—์„œ ๊ฒ€ํ† ํ•œ ๋ชจ๋“  ์ˆ˜์ค€์—์„œ๋Š” 300 ยฐC ์˜จ๋„๋ฅผ ์ „ํ›„๋กœ ์‘๋ ฅ-๋ณ€ํ˜• ๊ณก์„ ์˜ ๊ธฐ์šธ๊ธฐ๊ฐ€ ๋‹ฌ๋ผ์ง€๋Š” ํŠน์ง•์„ ๋ณด์˜€๋‹ค. 300 ยฐC ์ดํ•˜์˜ ์˜จ๋„์—์„œ ์‘๋ ฅ-๋ณ€ํ˜• ๊ณก์„ ์˜ ๊ธฐ์šธ๊ธฐ๋Š” ๊ฐ€์—ด๋˜์ง€ ์•Š์€ ์‹œํ—˜์ฒด์˜ ์‘๋ ฅ-๋ณ€ํ˜• ๊ณก์„ ์˜ ๊ธฐ์šธ๊ธฐ์™€ ํฐ ์ฐจ์ด๋ฅผ ๋ณด์ด์ง€ ์•Š๊ณ , ๋ณ€ํ˜•์€ ์ตœ๋Œ€์‘๋ ฅ๊นŒ์ง€ ์ง์„ ์— ๊ฐ€๊นŒ์šด ํ˜•ํƒœ๋กœ ์ฆ๊ฐ€ํ–ˆ๋‹ค. 500 ยฐC ์ด์ƒ์—์„œ ์‘๋ ฅ-๋ณ€ํ˜• ๊ณก์„ ์˜ ๊ธฐ์šธ๊ธฐ๋Š” ๊ฐ€์—ด์˜จ๋„๊ฐ€ ์ฆ๊ฐ€ํ•จ์— ๋”ฐ๋ผ ๋‚ฎ์•„์ง€๋Š” ๊ฒฝํ–ฅ์„ ๋‚˜ํƒ€๋ƒˆ๋‹ค.

Fig. 4. Stress-strain curve

../../Resources/kci/JKCI.2020.32.1.019/fig4.png

Fig. 5์— ์ตœ๋Œ€๋ณ€ํ˜•์„ ๋‚˜ํƒ€๋ƒˆ๋‹ค. 300 ยฐC ์ดํ•˜์˜ ์˜จ๋„์— ๋…ธ์ถœ๋˜์—ˆ๋˜ ์‹œํ—˜์ฒด์˜ ์ตœ๋Œ€๋ณ€ํ˜•์€ ๊ฐ€์—ด์˜จ๋„๊ฐ€ ์ฆ๊ฐ€ํ• ์ˆ˜๋ก ์•ฝ๊ฐ„ ์ฆ๊ฐ€ํ•˜๋Š” ๊ฒฝํ–ฅ์„ ๋ณด์˜€์ง€๋งŒ, ๊ทธ ๊ฐ’์€ 0.004 ์ดํ•˜๋กœ ๋‚˜ํƒ€๋‚ฌ๋‹ค. ์ผ๋ฐ˜์ ์œผ๋กœ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ํŒŒ๊ดด ๋ณ€ํ˜•๋ฅ ์˜ ๋ฒ”์œ„๊ฐ€ 0.0025~0.004์ธ ๊ฒƒ์„ ๊ณ ๋ คํ–ˆ์„ ๋•Œ, 300 ยฐC ์ดํ•˜์—์„œ ๊ฐ€์—ด์„ ๋ฐ›์ง€ ์•Š์€ ์ฝ˜ํฌ๋ฆฌํŠธ์™€ ์œ ์‚ฌํ•œ ๊ฑฐ๋™์„ ํ•˜๋Š” ๊ฒƒ์œผ๋กœ ์ƒ๊ฐํ•  ์ˆ˜ ์žˆ๋‹ค. 500 ๋ฐ 700 ยฐC์—์„œ๋Š” ๊ฐ€์—ด์˜จ๋„๊ฐ€ ๋†’์•„์ง์— ๋”ฐ๋ผ ์ตœ๋Œ€๋ณ€ํ˜•์ด ์ฆ๊ฐ€ํ–ˆ๊ณ  ๊ทธ ๊ฐ’์€ 500 ยฐC์—์„œ 0.0054~0.0068์˜ ๋ฒ”์œ„์ด๊ณ , 700 ยฐC์—์„œ 0.010~0.012๊นŒ์ง€ ์ฆ๊ฐ€ํ–ˆ๋‹ค. ๋™์ผํ•œ ์••์ถ•๊ฐ•๋„ ์ˆ˜์ค€์—์„œ ๋น„์ •์งˆ ๊ฐ•์„ฌ์œ ์˜ ํ˜ผ์ž…๋ฅ ์ด ์ฆ๊ฐ€ํ• ์ˆ˜๋ก ์ตœ๋Œ€๋ณ€ํ˜•์ด ์ž‘์•„์ง€๋Š” ๊ฒฝํ–ฅ์„ ํ™•์ธํ•  ์ˆ˜ ์žˆ์—ˆ๋‹ค.

Fig. 5. Peak strain

../../Resources/kci/JKCI.2020.32.1.019/fig5.png

์ด์™€ ๊ฐ™์€ ๊ฒฝํ–ฅ์€ ๊ณ ์˜จ ๊ฐ€์—ด์— ์˜ํ•œ ๋ฐœ์ƒํ•˜๋Š” ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ๊ท ์—ด ๊ฑฐ๋™์œผ๋กœ ์„ค๋ช…๋  ์ˆ˜ ์žˆ๋‹ค. Chang et al.(2006)์˜ ๋ณด๊ณ ์— ๋”ฐ๋ฅด๋ฉด 300 ยฐC ์ด์ƒ์˜ ์˜จ๋„์—์„œ๋Š” ์ฝ˜ํฌ๋ฆฌํŠธ ํ‘œ๋ฉด์— ๊ฐ€์‹œ์ ์ธ ๊ท ์—ด์ด ๊ด€์ฐฐ๋˜๋ฉฐ ๊ฐ€์—ด์˜จ๋„๊ฐ€ ์ฆ๊ฐ€ํ• ์ˆ˜๋ก ๊ท ์—ด์˜ ํญ์ด ํ™•์žฅ๋œ๋‹ค. ๋”ฐ๋ผ์„œ, 300 ยฐC ์ด์ƒ์—์„œ ์ตœ๋Œ€๋ณ€ํ˜•์˜ ๊ธ‰๊ฒฉํ•œ ์ฆ๊ฐ€์˜ ์›์ธ์€ ๊ตต์€ ๊ณจ์žฌ์™€ ์‹œ๋ฉ˜ํŠธ ํŽ˜์ด์ŠคํŠธ์˜ ์—ดํŒฝ์ฐฝ ์ฐจ์ด์— ์˜ํ•œ ๊ท ์—ด์˜ ๋ฐœ์ƒ๊ณผ ํ™•์žฅ์ธ ๊ฒƒ์œผ๋กœ ์ƒ๊ฐํ•  ์ˆ˜ ์žˆ๋‹ค. ๋˜ํ•œ, ๋น„์ •์งˆ ๊ฐ•์„ฌ์œ ์˜ ํ˜ผ์ž…์œผ๋กœ ๊ฐ€์—ด๋˜๋Š” ๋™์•ˆ ๋ฐœ์ƒํ•˜๋Š” ์ฝ˜ํฌ๋ฆฌํŠธ ๊ท ์—ด์˜ ํ™•์žฅ์ด ์–ต์ œ๋˜์–ด ํŒฝ์ฐฝ๋Ÿ‰์ด ์ ์–ด์ง€๊ธฐ ๋•Œ๋ฌธ์— ์žฌํ•˜์— ์˜ํ•œ ์ˆ˜์ถ•๋ณ€ํ˜•๊ณผ ์ตœ๋Œ€๋ณ€ํ˜•์ด ์ž‘์•„์ง„๋‹ค๊ณ  ํŒ๋‹จํ•  ์ˆ˜ ์žˆ๋‹ค.

3.2 ์••์ถ•๊ฐ•๋„

Table 4์— ๊ฐ€์—ด์˜จ๋„์— ๋”ฐ๋ฅธ ์„ฌ์œ ๋ณด๊ฐ• ๊ณ ๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์••์ถ•๊ฐ•๋„๋ฅผ ๋‚˜ํƒ€๋ƒˆ๋‹ค. ์ผ๋ฐ˜์ ์œผ๋กœ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์••์ถ•๊ฐ•๋„๋Š” ์˜จ๋„์ฆ๊ฐ€์— ๋”ฐ๋ผ ์„ ํ˜•์ ์œผ๋กœ ๊ฐ์†Œํ•œ๋‹ค๊ณ  ์ธ์‹๋˜๊ณ  ์žˆ๋‹ค. ๊ทธ๋Ÿฌ๋‚˜, ์ด ์—ฐ๊ตฌ์—์„œ๋Š” 300 ยฐC ์ดํ•˜์—์„œ ๊ฐ€์—ด์˜จ๋„๊ฐ€ ๋†’์•„์ง์—๋„ ๋ถˆ๊ตฌํ•˜๊ณ  ์••์ถ•๊ฐ•๋„๊ฐ€ ์ผ๋ถ€ ์ƒ์Šนํ•˜๋Š” ํ˜„์ƒ์„ ๋‚˜ํƒ€๋ƒˆ๋‹ค. ์ด์™€ ๊ฐ™์€ ๊ฒฝํ–ฅ์€ ๊ธฐ์กด์˜ ์—ฌ๋Ÿฌ ์—ฐ๊ตฌ์—์„œ๋„ ๊ด€์ฐฐ๋˜๊ณ  ์žˆ์œผ๋ฉฐ, ๊ทธ ์›์ธ์€ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ๋‚ด๋ถ€ ์ˆ˜๋ถ„๋Ÿ‰์ด ๊ฐ์†Œํ•จ์œผ๋กœ์จ ๊ฒ” ์ž…์ž ์‚ฌ์ด์˜ ๋ฐœ์ƒํ•˜๋Š” ๋ฐ˜๋ฐ๋ฅด๋ฐœ์Šค ํž˜์˜ ์ฆ๊ฐ€ ๋˜๋Š” ๋ฏธ ์ˆ˜ํ™”๋œ ์‹œ๋ฉ˜ํŠธ์˜ ์ˆ˜ํ™” ๋ฐ˜์‘์— ์˜ํ•œ ์••์ถ•๊ฐ•๋„์˜ ์ƒ์Šน๋Ÿ‰์œผ๋กœ ๋ถ„์„๋˜๊ณ  ์žˆ๋‹ค(Phan 1996; Behnood and Ghandehari 2009; Zheng et al. 2012).

Table 4. Compressive strength (MPa) with heating temperature

20 ยฐC

100 ยฐC

200 ยฐC

300 ยฐC

500 ยฐC

700 ยฐC

100P15

100.50

115.48

108.61

105.49

69.91

38.70

100P15A30

105.05

106.11

112.98

111.11

76.15

38.08

100P15A50

97.38

105.49

107.36

115.48

74.90

35.58

120P25

119.22

129.83

107.36

134.83

89.26

36.83

120P25A30

122.97

119.85

119.85

142.32

85.52

26.22

120P25A50

121.72

139.20

118.60

148.00

92.38

34.33

300 ยฐC ์ด์ƒ์—์„œ ์„ฌ์œ ๋ณด๊ฐ• ๊ณ ๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์••์ถ•๊ฐ•๋„๋Š” ์˜จ๋„๊ฐ€ ์ฆ๊ฐ€ํ•จ์— ๋”ฐ๋ผ ์„ ํ˜•์ ์œผ๋กœ ๊ฐ์†Œํ•˜๋Š” ํ•ญ๊ตฌ์  ๊ฐ•๋„ ์ƒ์‹ค ๊ตฌ๊ฐ„์„ ๋‚˜ํƒ€๋ƒˆ๋‹ค(Phan 2002). ์•ž์„œ ์„ค๋ช…ํ•œ ๋ฐ”์™€ ๊ฐ™์ด 300 ยฐC ์ด์ƒ์˜ ๊ฐ€์—ด์„ ๋ฐ›๋Š” ์ฝ˜ํฌ๋ฆฌํŠธ์—์„œ๋Š” ๊ฐ€์‹œ์  ๊ท ์—ด์˜ ๋ฐœ์ƒ๊ณผ 500 ยฐC ์ด์ƒ์—์„œ ์ˆ˜ํ™”๊ฒฝํ™”์ฒด(Ca(OH)2)๊ฐ€ ๋ถ•๊ดดํ•˜๊ธฐ ๋•Œ๋ฌธ์— ๊ฐ•๋„์˜ ์ƒ์Šน์„ ๊ธฐ๋Œ€ํ•  ์ˆ˜ ์—†๊ณ , ์˜จ๋„์ฆ๊ฐ€์™€ ํ•จ๊ป˜ ์••์ถ•๊ฐ•๋„๋Š” ์ €ํ•˜ํ•œ๋‹ค. ํ•œํŽธ, 300 ยฐC ์ด์ƒ์—์„œ ๋น„์ •์งˆ ๊ฐ•์„ฌ์œ ๊ฐ€ ํฌํ•จ๋œ ์‹œํ—˜์ฒด์˜ ์••์ถ•๊ฐ•๋„๋Š” ํด๋ฆฌํ”„๋กœํ•„๋ Œ ์„ฌ์œ ๋งŒ์„ ํ˜ผ์ž…ํ•œ ์‹œํ—˜์ฒด์— ๋น„ํ•ด ์ฆ๊ฐ€ํ•˜์˜€๋‹ค. ํƒ„์„ฑ๊ณ„์ˆ˜๊ฐ€ ๋†’์€ ๊ฐ•์„ฌ์œ ๋‚˜ ํƒ„์†Œ์„ฌ์œ ๊ฐ€ ์ฝ˜ํฌ๋ฆฌํŠธ์— ํ˜ผ์ž…๋  ๋•Œ๋Š” ์„ฌ์œ ์˜ ๊ฐ€๊ต ์ž‘์šฉ ๋ฐ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ๊ท ์—ด์„ ์ œ์–ดํ•จ์œผ๋กœ์จ ์••์ถ•๊ฐ•๋„์˜ ๊ฐœ์„ ์— ํšจ๊ณผ์ ์ธ ๊ฒƒ์œผ๋กœ ์•Œ๋ ค์ ธ ์žˆ๋‹ค(Chen and Liu 2004). ๋”ฐ๋ผ์„œ, ๋น„์ •์งˆ ๊ฐ•์„ฌ์œ ๊ฐ€ ํ˜ผ์ž…๋œ ๊ฒฝ์šฐ, ๊ณ ์˜จ์—์„œ ๋ฐœ์ƒํ•˜๋Š” ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ๊ท ์—ด์ด ์ œ์–ด๋˜๊ณ  ์••์ถ•๊ฐ•๋„ ์ €ํ•˜๊ฐ€ ๊ฐœ์„ ๋˜๋Š” ๊ฒƒ์œผ๋กœ ์ƒ๊ฐ๋œ๋‹ค.

Fig. 6์€ ๊ฐ€์—ด์˜จ๋„์— ๋”ฐ๋ฅธ ์„ฌ์œ ๋ณด๊ฐ• ๊ณ ๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์••์ถ•๊ฐ•๋„ ๋น„๋ฅผ BS EN 1992-1-2;2004(CEN 2004) ๋ชจ๋ธ๊ณผ Phan (2002) ๋ชจ๋ธ์„ ๋น„๊ตํ•ด์„œ ๋‚˜ํƒ€๋ƒˆ๋‹ค. ๋‘ ๋ชจ๋ธ์€ ๊ฐ๊ฐ ์ผ๋ฐ˜๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ์™€ ๊ณ ๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ๋ฅผ ๋Œ€์ƒ์œผ๋กœ ํ•œ ํŠน์ง•์ด ์žˆ๋‹ค. 300 ยฐC ์ดํ•˜์—์„œ ์••์ถ•๊ฐ•๋„ ๋น„๊ฐ€ BS EN 1992-1-2;2004(CEN 2004) ๋ชจ๋ธ์ด Phan(2002) ๋ชจ๋ธ๋ณด๋‹ค ๋†’์€ ๊ฒƒ์„ ์•Œ ์ˆ˜ ์žˆ๋Š”๋ฐ ๋ชจ๋‘ 300 ยฐC ์ดํ•˜์—์„œ ๋ฐœ์ƒํ•˜๋Š” ๋ถˆ๊ทœ์น™์ ์ธ ์••์ถ•๊ฐ•๋„์˜ ๊ฑฐ๋™์„ ๊ณ ๋ คํ•˜์ง€ ์•Š๊ณ  ์žˆ๊ธฐ ๋•Œ๋ฌธ์ด๋‹ค. ํ•œํŽธ, 500 ยฐC ์ด์ƒ์—์„œ๋Š” ์ผ๋ฐ˜๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ ๋ฒ”์œ„์ธ BS EN 1992-1-2;2004(CEN 2004) ๋ชจ๋ธ๊ณผ ์œ ์‚ฌํ•œ ๊ฐ’์„ ๋‚˜ํƒ€๋ƒˆ๋‹ค. ์ผ๋ฐ˜์ ์œผ๋กœ ๊ณ ๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ๋Š” ์ผ๋ฐ˜๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ๋ณด๋‹ค ๊ณ ์˜จ์— ์˜ํ•œ ์••์ถ•๊ฐ•๋„์˜ ๊ฐ์†Œ์œจ์ด ๋†’์€ ๊ฒƒ์œผ๋กœ ์•Œ๋ ค์ ธ ์žˆ๋‹ค. ๋”ฐ๋ผ์„œ, ์ด ์—ฐ๊ตฌ์—์„œ๋Š” ํด๋ฆฌํ”„๋กœํ•„๋ Œ ์„ฌ์œ ์™€ ๋น„์ •์งˆ ๊ฐ•์„ฌ์œ ์˜ ํ˜ผ์ž…์— ์˜ํ•ด ๊ณ ๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์••์ถ•๊ฐ•๋„ ์ €ํ•˜์œจ์„ ์ผ๋ฐ˜๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์ˆ˜์ค€์œผ๋กœ ์ œ์–ดํ•  ์ˆ˜ ์žˆ์—ˆ๋‹ค.

Fig. 6. Ratio of compressive strength

../../Resources/kci/JKCI.2020.32.1.019/fig6.png

3.3 ํƒ„์„ฑ๊ณ„์ˆ˜

Table 5๋Š” ๊ฐ€์—ด์˜จ๋„์— ๋”ฐ๋ฅธ ์„ฌ์œ ๋ณด๊ฐ• ๊ณ ๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ํƒ„์„ฑ๊ณ„์ˆ˜๋ฅผ ๋‚˜ํƒ€๋‚ธ๋‹ค. ์ด ์—ฐ๊ตฌ์—์„œ ๊ฒ€ํ† ํ•œ ๋ชจ๋“  ์ˆ˜์ค€์—์„œ ๊ณ ๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ํƒ„์„ฑ๊ณ„์ˆ˜๋Š” โ€‹โ€‹์˜จ๋„๊ฐ€ ์ฆ๊ฐ€ํ•จ์— ๋”ฐ๋ผ ๊ฑฐ์˜ ์„ ํ˜•์— ๊ฐ€๊น๊ฒŒ ๊ฐ์†Œํ•˜๋Š” ๊ฒฝํ–ฅ์„ ๋ณด์˜€๋‹ค. 300 ยฐC ์ดํ•˜์˜ ์˜จ๋„์—์„œ ์••์ถ•๊ฐ•๋„๊ฐ€ ์œ ์ง€ ๋˜๋Š” ์ƒ์Šนํ•˜๋Š” ๊ฒƒ๊ณผ ๋น„๊ตํ•ด์„œ ๋งค์šฐ ๋‹ค๋ฅธ ๊ฒฐ๊ณผ์ด์ง€๋งŒ ์ผ๋ฐ˜์ ์œผ๋กœ ๋™์ผํ•œ ์˜จ๋„์—์„œ๋Š” ์••์ถ•๊ฐ•๋„๋ณด๋‹ค ํƒ„์„ฑ๊ณ„์ˆ˜๊ฐ€ ํฌ๊ฒŒ ์ €ํ•˜๋˜๊ณ , ํƒ„์„ฑ๊ณ„์ˆ˜๋Š” ๊ฐ€์—ด์˜จ๋„์˜ ์˜ํ–ฅ์„ ๊ฐ€์žฅ ๋งŽ์ด ๋ฐ›๋Š” ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ํŠน์„ฑ์— ๊ธฐ์ธํ•œ ๊ฒƒ์œผ๋กœ ์—ฌ๋Ÿฌ ์—ฐ๊ตฌ๋ฅผ ํ†ตํ•ด์„œ ๋ณด๊ณ ๋˜๊ณ  ์žˆ๋‹ค(Nassif et al. 1995; Chang et al. 2006; Vieira et al. 2011; Yermak et al. 2017). ํ•œํŽธ, 300 ยฐC๊นŒ์ง€์˜ ๊ฐ€์—ด์˜จ๋„์—์„œ๋Š” ๊ฐ€์—ด๋˜์ง€ ์•Š์€ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์••์ถ•๊ฐ•๋„๊ฐ€ ๋†’์„์ˆ˜๋ก ํƒ„์„ฑ๊ณ„์ˆ˜๊ฐ€ ๋†’์•˜๋‹ค. ๋˜ํ•œ, ๋™์ผํ•œ ์••์ถ•๊ฐ•๋„์—์„œ๋Š” ๋น„์ •์งˆ ๊ฐ•์„ฌ์œ ์˜ ํ˜ผ์ž…๋Ÿ‰์ด ๋งŽ์„์ˆ˜๋ก ๊ณ ์˜จ์— ์˜ํ•œ ํƒ„์„ฑ๊ณ„์ˆ˜์˜ ์ €ํ•˜๊ฐ€ ์ž‘์•„์ง€๋Š” ๊ฒฝํ–ฅ์„ ๋ณด์˜€๋‹ค. ํƒ„์„ฑ๊ณ„์ˆ˜์˜ ์ €ํ•˜๋Š” ๊ฐ€์—ด์„ ๋ฐ›๋Š” ์ฝ˜ํฌ๋ฆฌํŠธ์—์„œ ๋ฐœ์ƒํ•˜๋Š” ๊ท ์—ด๊ณผ ํฐ ๊ด€๊ณ„๊ฐ€ ์žˆ๊ธฐ ๋•Œ๋ฌธ์—(Chang et al. 2006; Vieira et al. 2011; Yermak et al. 2017) ๋น„์ •์งˆ ๊ฐ•์„ฌ์œ ๊ฐ€ ํ˜ผ์ž…๋œ ์ฝ˜ํฌ๋ฆฌํŠธ์—์„œ๋Š” ๊ฐ€์—ด์— ์˜ํ•ด ๋ฐœ์ƒํ•˜๋Š” ๋งคํŠธ๋ฆญ์Šค ๊ท ์—ด์˜ ๋ฐœ์ƒ์„ ์–ต์ œํ•จ์œผ๋กœ์จ ์••์ถ•๊ฐ•๋„๋ฟ๋งŒ ์•„๋‹ˆ๋ผ ํƒ„์„ฑ๊ณ„์ˆ˜ ์ €ํ•˜์˜ ๋ฌธ์ œ์—์„œ๋„ ์œ ํšจํ•œ ๊ฒƒ์œผ๋กœ ์ƒ๊ฐ๋œ๋‹ค. ๊ทธ๋Ÿฌ๋‚˜ 500 ยฐC ์ด์ƒ์˜ ๊ฐ€์—ด์˜จ๋„์—์„œ๋Š” ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์••์ถ•๊ฐ•๋„๋‚˜ ์„ฌ์œ ํ˜ผ์ž…์กฐ๊ฑด๊ณผ ๊ด€๊ณ„์—†์ด ๋ชจ๋“  ์‹œํ—˜์ฒด์˜ ํƒ„์„ฑ๊ณ„์ˆ˜๊ฐ€ ์œ ์‚ฌํ•œ ๊ฐ’์„ ๋‚˜ํƒ€๋ƒˆ๋‹ค.

Table 5. Elastic modulus (GPa) with heating temperature

20 ยฐC

100 ยฐC

200 ยฐC

300 ยฐC

500 ยฐC

700 ยฐC

100P15

43.74

41.06

34.69

28.84

11.81

2.39

100P15A30

45.03

43.05

37.41

30.32

10.13

2.16

100P15A50

45.56

43.20

39.57

33.69

9.87

2.49

120P25

46.86

45.10

41.55

34.63

11.70

2.30

120P25A30

50.79

49.43

44.18

38.20

10.86

2.26

120P25A50

52.51

51.06

45.44

40.88

11.27

2.54

Fig. 7์— ๊ฐ€์—ด์˜จ๋„์— ๋”ฐ๋ฅธ ์„ฌ์œ ๋ณด๊ฐ• ๊ณ ๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ํƒ„์„ฑ๊ณ„์ˆ˜ ๋น„๋ฅผ BS EN 1992-1-2;2004(CEN 2004)์—์„œ ์ œ์‹œํ•˜๊ณ  ์žˆ๋Š” ๋ชจ๋ธ, Chang et al.(2006)์ด ์ œ์•ˆํ•œ ๋ชจ๋ธ๊ณผ ๋น„๊ตํ•ด์„œ ๋‚˜ํƒ€๋ƒˆ๋‹ค. ์ด ์—ฐ๊ตฌ์—์„œ ์–ป์–ด์ง„ ํƒ„์„ฑ๊ณ„์ˆ˜์˜ ๋น„๋Š” 100~300 ยฐC์˜ ์˜จ๋„ ๋ฒ”์œ„์—์„œ BS EN 1992-1-2:2004(CEN 2004)์˜ ๋ชจ๋ธ๊ณผ ์ƒ๋‹นํžˆ ํฐ ์ฐจ์ด๋ฅผ ๋‚˜ํƒ€๋ƒˆ๋‹ค. 500 ยฐC์˜ ๊ฐ€์—ด์˜จ๋„์—์„œ๋Š” ๊ทธ ๊ฒฉ์ฐจ๊ฐ€ ๊ฐ์†Œํ•˜์ง€๋งŒ ์—ฌ์ „ํžˆ ๋‘ ๋ฐฐ ์ด์ƒ์˜ ์ฐจ์ด๋ฅผ ๋ณด์˜€์œผ๋ฉฐ, 700 ยฐC์—์„œ ์œ ์‚ฌํ•œ ๊ฐ’์„ ๋‚˜ํƒ€๋ƒˆ๋‹ค. ์ด ์ฐจ์ด๋Š” ํƒ„์„ฑ๊ณ„์ˆ˜์™€ ๋ฐ€์ ‘ํ•œ ๊ด€๊ณ„๋ฅผ ์ฐพ๋Š” ์ตœ๋Œ€๋ณ€ํ˜•์˜ ์ฐจ์ด๋กœ ์„ค๋ช…๋œ๋‹ค. BS EN 1992-1- 2;2004(CEN 2004)์—์„œ๋Š” 300 ยฐC๊นŒ์ง€ ์˜จ๋„์ฆ๊ฐ€์— ๋”ฐ๋ผ ์ตœ๋Œ€๋ณ€ํ˜•์ด ์ƒ์˜จ๋ณด๋‹ค ์•ฝ 3๋ฐฐ ์ฆ๊ฐ€ํ•˜๋Š” ๊ฒƒ์œผ๋กœ ์ œ์‹œ๋˜๊ณ  ์žˆ์ง€๋งŒ, ์—ฐ๊ตฌ์—์„œ๋Š” ๊ฐ™์€ ์˜จ๋„ ๋ฒ”์œ„์—์„œ ์ตœ๋Œ€๋ณ€ํ˜•์˜ ๋ณ€ํ™”๊ฐ€ ๋งค์šฐ ์ ์—ˆ๋‹ค.

Fig. 7. Ratio of elastic modulus

../../Resources/kci/JKCI.2020.32.1.019/fig7.png

ํ•œํŽธ, Chang et al.(2006)์ด ์ œ์‹œํ•œ ๋ชจ๋ธ์€ ์••์ถ•๊ฐ•๋„ 27 MPa์™€ 40 MPa์˜ ์ฝ˜ํฌ๋ฆฌํŠธ์— ๋Œ€ํ•œ ๊ฒ€ํ† ๋ฅผ ํ†ตํ•ด ๋งŒ๋“ค์–ด์ง„ ๊ฒƒ์ž„์—๋„ ๋ถˆ๊ตฌํ•˜๊ณ  ์ด ์—ฐ๊ตฌ์˜ ๊ฒฐ๊ณผ์™€ ์œ ์‚ฌํ•œ ๊ฒฝํ–ฅ์„ ๋ณด์˜€๋‹ค. ์ด๋กœ๋ถ€ํ„ฐ ๊ณ ์˜จ์„ ๋ฐ›์€ ํƒ„์„ฑ๊ณ„์ˆ˜๋Š” ๊ฐ€์—ด์„ ๋ฐ›์ง€ ์•Š์€ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์••์ถ•๊ฐ•๋„๋ณด๋‹ค ๊ฐ€์—ด์˜จ๋„์˜ ์˜ํ–ฅ์ด ์ง€๋ฐฐ์ ์ธ ๊ฒƒ์œผ๋กœ ๋‚˜ํƒ€๋‚ฌ๋‹ค.

3.4 ์—ดํŒฝ์ฐฝ๋ณ€ํ˜•

Fig. 8์— 700 ยฐC๊นŒ์ง€ ๊ฐ€์—ด๋˜๋Š” ๋™์•ˆ ์„ฌ์œ ๋ณด๊ฐ• ๊ณ ๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ ์‹œํ—˜์ฒด์—์„œ ๋ฐœ์ƒํ•˜๋Š” ์—ดํŒฝ์ฐฝ๋ณ€ํ˜•์„ ๋‚˜ํƒ€๋ƒˆ๋‹ค. ์—ดํŒฝ์ฐฝ๋ณ€ํ˜•์€ 400 ยฐC๊นŒ์ง€ ๋น„๊ต์  ์„ ํ˜•์— ๊ฐ€๊นŒ์šด ์ƒ์Šน๊ณก์„ ์„ ๋ณด์ด๋ฉฐ, 400 ยฐC ์ด์ƒ์—์„œ ๊ธ‰๊ฒฉํžˆ ์ฆ๊ฐ€ํ•˜๊ธฐ ์‹œ์ž‘ํ–ˆ๋‹ค. ์ดํ›„, 600~ 700 ยฐC์˜ ์˜จ๋„ ๊ตฌ๊ฐ„์—์„œ๋Š” ๋”๋Š” ํŒฝ์ฐฝํ•˜์ง€ ์•Š๊ณ  ์ˆ˜๋ ดํ•˜๋Š” ๊ฒฝํ–ฅ์„ ๋ณด์˜€๋‹ค. ์ด ๊ฐ™์€ ์—ดํŒฝ์ฐฝ๋ณ€ํ˜•์˜ ํ˜•ํƒœ๋Š” ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์••์ถ•๊ฐ•๋„ ๋˜๋Š” ์„ฌ์œ ํ˜ผ์ž…์กฐ๊ฑด๊ณผ ๊ด€๊ณ„์—†์ด ์œ ์‚ฌํ•˜๊ฒŒ ๋‚˜ํƒ€๋‚ฌ์œผ๋ฉฐ ๊ทธ ๊ฐ’๋„ ํฐ ์ฐจ์ด๋ฅผ ๋ณด์ด์ง€๋Š” ์•Š์•˜๋‹ค. ์ด ์—ฐ๊ตฌ์—์„œ ์ธก์ •๋œ ์„ฌ์œ ๋ณด๊ฐ• ๊ณ ๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์—ดํŒฝ์ฐฝ๋ณ€ํ˜• ๊ฑฐ๋™์€ ์ „์ฒด์ ์œผ๋กœ BS EN 1992-1-2004(CEN 2004)์—์„œ ์ œ์‹œํ•˜๊ณ  ์žˆ๋Š” ๋‘ ๊ฐ€์ง€ ์—ดํŒฝ์ฐฝ๋ชจ๋ธ(siliceous aggregate concrete, calcareous aggregate concrete)์˜ ์‚ฌ์ด์— ์œ„์น˜ํ•˜๋Š” ๊ฒƒ์„ ์•Œ ์ˆ˜ ์žˆ๋‹ค.

Fig. 8. hermal expansion strain

../../Resources/kci/JKCI.2020.32.1.019/fig8.png

์ผ๋ฐ˜์ ์œผ๋กœ ๊ฐ€์—ด๋˜๋Š” ์ฝ˜ํฌ๋ฆฌํŠธ๋Š” ํŒฝ์ฐฝํ•˜๋Š”๋ฐ, ๊ฐ€์—ด์˜จ๋„์— ๋”ฐ๋ฅธ ์ฐจ์ด๋Š” ๊ตฌ์„ฑ ์žฌ๋ฃŒ์˜ ์˜ํ–ฅ์„ ๋ฐ›๋Š”๋‹ค. ์‹œ๋ฉ˜ํŠธ ํŽ˜์ด์ŠคํŠธ ๋ฐ ๊ตต์€ ๊ณจ์žฌ๋Š” 80~90 ยฐC์˜ ์˜จ๋„๊นŒ์ง€๋Š” ๋ชจ๋‘ ํŒฝ์ฐฝํ•˜์ง€๋งŒ, 110 ยฐC ์ด์ƒ์ด ๋˜๋ฉด ๊ตต์€ ๊ณจ์žฌ๋Š” ํŒฝ์ฐฝ ๊ฑฐ๋™์ด ๊ณ„์†๋˜๋Š” ๋ฐ˜๋ฉด์— ์‹œ๋ฉ˜ํŠธ ํŽ˜์ด์ŠคํŠธ๋Š” ์ˆ˜๋ถ„์˜ ์ฆ๋ฐœ๋กœ ์ธํ•ด ์ˆ˜์ถ•ํ•˜๊ฒŒ ๋œ๋‹ค. ๊ตต์€ ๊ณจ์žฌ์˜ ํŒฝ์ฐฝ์€ ์‹œ๋ฉ˜ํŠธ ํŽ˜์ด์ŠคํŠธ์˜ ์ˆ˜์ถ•๋ณด๋‹ค ๋” ํฌ๊ฒŒ ๋ฐœ์ƒํ•˜๊ธฐ ๋•Œ๋ฌธ์—(Schneider 1988) ๊ตต์€ ๊ณจ์žฌ์˜ ์ข…๋ฅ˜๋Š” ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์—ดํŒฝ์ฐฝ๋ณ€ํ˜•์— ๋งค์šฐ ํฐ ์˜ํ–ฅ์„ ๋ฏธ์นœ๋‹ค. ์ด ์—ฐ๊ตฌ์—์„œ ๊ฒ€ํ† ๋œ ์„ฌ์œ ๋ณด๊ฐ• ๊ณ ๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ๊ฐ€ ์—ดํŒฝ์ฐฝ๋ณ€ํ˜•์—์„œ ํฐ ์ฐจ์ด๋ฅผ ๋ณด์ด์ง€ ์•Š๋Š” ๊ฒƒ์€ ์—ดํŒฝ์ฐฝ๋ณ€ํ˜•์— ์ง€๋ฐฐ์ ์ธ ์˜ํ–ฅ์„ ๋ฏธ์น˜๋Š” ๊ตต์€ ๊ณจ์žฌ๊ฐ€ ๋™์ผํ•˜๊ธฐ ๋•Œ๋ฌธ์œผ๋กœ ์ƒ๊ฐํ•  ์ˆ˜ ์žˆ๋‹ค.

ํ•œํŽธ, ๋™์ผํ•œ ์••์ถ•๊ฐ•๋„์˜ ์ฝ˜ํฌ๋ฆฌํŠธ๋ฅผ ์‚ฌ์šฉํ•œ ์‹œํ—˜์ฒด์—์„œ๋Š” ๋น„์ •์งˆ ๊ฐ•์„ฌ์œ ์˜ ํ˜ผ์ž…๋Ÿ‰์ด ์ฆ๊ฐ€ํ• ์ˆ˜๋ก 400 ยฐC ์ด์ƒ์˜ ์˜จ๋„์—์„œ ๋น„๊ต์  ์—ดํŒฝ์ฐฝ๋ณ€ํ˜• ์ž‘์•˜๋‹ค. ๊ตต์€ ๊ณจ์žฌ์™€ ์‹œ๋ฉ˜ํŠธ ํŽ˜์ด์ŠคํŠธ์˜ ๋‹ค๋ฅธ ์—ดํŒฝ์ฐฝ ๊ฑฐ๋™์ด ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์—ดํŒฝ์ฐฝ๋ณ€ํ˜•์— ์˜ํ–ฅ์„ ๋ฏธ์นœ๋‹ค๋Š” ์‚ฌ์‹ค์€ ์ด๋ฏธ ์•ž์„œ ์ž์„ธํžˆ ์–ธ๊ธ‰ํ–ˆ๋‹ค. Andiรง-ร‡akฤฑr and Hฤฑzal(2012)์˜ ์—ฐ๊ตฌ์— ๋”ฐ๋ฅด๋ฉด ๊ฐ€์—ด์˜จ๋„๊ฐ€ 300 ยฐC์— ๋„๋‹ฌํ•  ๊ฒฝ์šฐ ๊ตต์€ ๊ณจ์žฌ์™€ ์‹œ๋ฉ˜ํŠธ ํŽ˜์ด์ŠคํŠธ์˜ ๊ณ„๋ฉด์—์„œ ๊ท ์—ด์ด ๋ฐœ์ƒํ•˜๋Š” ๊ฒƒ์œผ๋กœ ๋ณด๊ณ ํ•˜์˜€์œผ๋ฉฐ, Choe et al.(2019)์˜ ์—ฐ๊ตฌ์—์„œ๋Š” ๊ฐ€์—ด์„ ๋ฐ›์€ ์ฝ˜ํฌ๋ฆฌํŠธ์— ๋ฐœ์ƒํ•˜๋Š” ์ˆ˜์ฆ๊ธฐ์••๋ ฅ๊ณผ ์—ดํŒฝ์ฐฝ๋ณ€ํ˜•์˜ ๊ด€๊ณ„๋ฅผ ๋ถ„์„ํ•จ์œผ๋กœ์จ ์ด ์˜จ๋„ ๋ฒ”์œ„์—์„œ ์ฝ˜ํฌ๋ฆฌํŠธ ์‹œํ—˜์ฒด ์ „๋ฐ˜์— ๊ฑธ์ณ ๋ฐœ์ƒํ•˜๋Š” ๊ท ์—ด์˜ ์กด์žฌ๋ฅผ ํ™•์ธํ•˜์˜€๋‹ค. ๋”ฐ๋ผ์„œ, 400 ยฐC ์ด์ƒ์˜ ์˜จ๋„์—์„œ ๊ธ‰๊ฒฉํ•œ ์—ดํŒฝ์ฐฝ๋ณ€ํ˜•์˜ ์ฆ๊ฐ€๋Š” ๊ฐ€์—ด์— ์˜ํ•ด ๋ฐœ์ƒํ•˜๋Š” ๊ท ์—ด์— ๊ธฐ์ธํ•˜๋Š” ๊ฒƒ์œผ๋กœ ์ถ”์ •ํ•  ์ˆ˜ ์žˆ๋‹ค. ๋น„์ •์งˆ ๊ฐ•์„ฌ์œ ๋ฅผ ํ˜ผ์ž…ํ•œ ๊ณ ๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ๋Š” ์„ฌ์œ ์˜ ๊ฐ€๊ต ์ž‘์šฉ์œผ๋กœ ๊ณ ์˜จ์— ์˜ํ•ด ์œ ๋ฐœ๋˜๋Š” ๊ท ์—ด์ด ์ œ์–ด๋˜๊ณ  ์—ดํŒฝ์ฐฝ๋ณ€ํ˜•์ด ์ƒ๋Œ€์ ์œผ๋กœ ์ž‘์€ ๊ฐ’์„ ๋‚˜ํƒ€๋‚ด๋Š” ๊ฒƒ์ด๋‹ค. ์ด์™€ ๊ฐ™์€ ์—ดํŒฝ์ฐฝ๋ณ€ํ˜•์˜ ํ˜•ํƒœ๋Š” ์•ž์„œ ๊ฒ€ํ† ํ•œ ์„ฌ์œ ๋ณด๊ฐ• ๊ณ ๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์••์ถ•๊ฐ•๋„, ํƒ„์„ฑ๊ณ„์ˆ˜, ํ”ผํฌ ๋ณ€ํ˜•์˜ ๊ฒฐ๊ณผ์™€ ์ผ์น˜ํ•œ๋‹ค. ๊ฐ€์—ด๋˜๋Š” ๋™์•ˆ ์—ฐ์†์ ์œผ๋กœ ์ธก์ •๋œ ์—ดํŒฝ์ฐฝ๋ณ€ํ˜•์˜ ๊ฑฐ๋™์œผ๋กœ๋ถ€ํ„ฐ ๋น„์ •์งˆ ๊ฐ•์„ฌ์œ ์˜ ํ˜ผ์ž…์œผ๋กœ ๊ฐ€์—ด๋˜๋Š” ๋™์•ˆ์˜ ์ฝ˜ํฌ๋ฆฌํŠธ ํŒฝ์ฐฝ๊ท ์—ด์ด ์ œ์–ด๋˜์–ด ๊ณ ์˜จ์— ์˜ํ•ด ์ €ํ•˜ํ•˜๋Š” ๊ณ ๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์—ญํ•™์  ํŠน์„ฑ์„ ๊ฐœ์„ ํ•˜๋Š” ๋ฐ ํšจ๊ณผ๊ฐ€ ์žˆ๋Š” ๊ฒƒ์œผ๋กœ ์ƒ๊ฐํ•  ์ˆ˜ ์žˆ๋‹ค.

4. ๊ฒฐ ๋ก 

๋น„์ •์งˆ ๊ฐ•์„ฌ์œ ๋ฅผ ๋ณด๊ฐ•ํ•œ ๊ณ ๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ๊ณ ์˜จ ์—ญํ•™์  ํŠน์„ฑ์„ ์‹คํ—˜์ ์œผ๋กœ ๊ฒ€ํ† ํ•œ ๊ฒฐ๊ณผ๋ฅผ ํ†ตํ•ด ๋ณธ ๋…ผ๋ฌธ์—์„œ๋Š” ๋‹ค์Œ๊ณผ ๊ฐ™์€ ๊ฒฐ๋ก ์„ ๋„์ถœํ•  ์ˆ˜ ์žˆ์—ˆ๋‹ค.

1) 300 ยฐC ์ด์ƒ์˜ ๊ณ ์˜จ์— ๋…ธ์ถœ๋œ ๋น„์ •์งˆ ๊ฐ•์„ฌ์œ  ๋ณด๊ฐ• ๊ณ ๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ ์‹œํ—˜์ฒด๋Š” ์••์ถ•๊ฐ•๋„์˜ ์ €ํ•˜์œจ์ด ๋‚ฎ์•„์ง€๋Š” ๊ฒฐ๊ณผ๋ฅผ ์–ป์—ˆ์œผ๋ฉฐ, ๋น„์ •์งˆ ๊ฐ•์„ฌ์œ ์˜ ํ˜ผ์ž…๋ฅ ์ด ์ฆ๊ฐ€ํ• ์ˆ˜๋ก ๊ณ ์˜จ์—์„œ ๊ณ ๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์••์ถ•๊ฐ•๋„ ๊ฐœ์„  ํšจ๊ณผ๊ฐ€ ๋” ์ปค์ง€๋Š” ๊ฒฝํ–ฅ์ด ํ™•์ธ๋˜์—ˆ๋‹ค.

2) ๊ณ ์˜จ์„ ๋ฐ›์€ ์„ฌ์œ ๋ณด๊ฐ• ๊ณ ๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ํƒ„์„ฑ๊ณ„์ˆ˜๋Š” ๊ฐ€์—ด์˜จ๋„๊ฐ€ ์ฆ๊ฐ€ํ• ์ˆ˜๋ก ์„ ํ˜•์ ์œผ๋กœ ๊ฐ์†Œํ•˜๋Š” ๊ฒฝํ–ฅ์„ ๋ณด์˜€๋‹ค. ๋˜ํ•œ, ๋น„์ •์งˆ ๊ฐ•์„ฌ์œ ์˜ ํ˜ผ์ž…์— ์˜ํ•ด ํƒ„์„ฑ๊ณ„์ˆ˜์˜ ์ €ํ•˜์œจ์ด ๊ฐœ์„ ๋˜๋Š” ํšจ๊ณผ๋ฅผ ์–ป์„ ์ˆ˜ ์žˆ์—ˆ์œผ๋‚˜, ์ „์ฒด์ ์ธ ๊ฒฝํ–ฅ์€ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ์••์ถ•๊ฐ•๋„๋‚˜ ์„ฌ์œ ํ˜ผ์ž…์กฐ๊ฑด์— ๋”ฐ๋ผ ํฐ ์ฐจ์ด๋ฅผ ๋‚˜ํƒ€๋‚ด์ง€ ์•Š์•˜๋‹ค.

3) ์ตœ๋Œ€๋ณ€ํ˜•๊ณผ ์—ดํŒฝ์ฐฝ๋ณ€ํ˜•์€ 300 ยฐC ์ด์ƒ์—์„œ ์„ฌ์œ ํ˜ผ์ž…์กฐ๊ฑด์— ๋”ฐ๋ฅธ ์ฐจ์ด๋ฅผ ๋ณด์˜€์œผ๋ฉฐ, ๋น„์ •์งˆ ๊ฐ•์„ฌ์œ ์˜ ํ˜ผ์ž…๋ฅ ์ด ์ฆ๊ฐ€ํ• ์ˆ˜๋ก ์„ฌ์œ ๋ณด๊ฐ• ๊ณ ๊ฐ•๋„ ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ๋ณ€ํ˜•์ด ์ž‘๊ฒŒ ๋ฐœ์ƒํ–ˆ๋‹ค. ๋น„์ •์งˆ ๊ฐ•์„ฌ์œ ๋ฅผ ํ˜ผ์ž…ํ•จ์œผ๋กœ์จ ๊ณจ์žฌ์˜ ํŒฝ์ฐฝ๊ณผ ์‹œ๋ฉ˜ํŠธ ํŽ˜์ด์ŠคํŠธ์˜ ์ˆ˜์ถ• ๊ด€๊ณ„์—์„œ ๋ฐœ์ƒํ•˜๋Š” ์ฝ˜ํฌ๋ฆฌํŠธ์˜ ๊ท ์—ด์„ ํšจ๊ณผ์ ์œผ๋กœ ์ œ์–ดํ•  ์ˆ˜ ์žˆ์œผ๋ฉฐ, ๊ณ ์˜จ์—์„œ์˜ ์—ญํ•™์  ํŠน์„ฑ์„ ๊ฐœ์„ ํ•  ์ˆ˜ ์žˆ๋Š” ๊ฒƒ์œผ๋กœ ํ™•์ธ๋˜์—ˆ๋‹ค.

๊ฐ์‚ฌ์˜ ๊ธ€

์ด ์—ฐ๊ตฌ๋Š” ์ถฉ๋‚จ๋Œ€ํ•™๊ต ํ•™์ˆ ์—ฐ๊ตฌ๋น„์— ์˜ํ•ด ์ง€์›๋˜์—ˆ์Šต๋‹ˆ๋‹ค. ์ด์— ๊ฐ์‚ฌ๋“œ๋ฆฝ๋‹ˆ๋‹ค.

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